Air conditioning system



April 28, 1936. y J, LAMB 2,038,579

AIR 'CONDITIONING SYSTEM vFiled Jan. 20, 1934 2 Sheets-Shel??I 1 WITNEss's; n n Q n Y V Y JFLamb.

,A E z 'BY April4 28, 1936. J. F. LAMB `AIR CONDITIONING SYSTEM l Filed Jan. 2o, 1934 2' sheets-sheet' z INVENTOR J. F.' Lamb.

f77 7i, i" i mm/ 24 d los Q7 I ATTORY WITNESSES Patented Apr. 28, 1936 UNITED STATES PATENT OFFICE Am CONDITIONING SYSTEM Sylvania Application January 20, 1934, Serial Nb. 707,540

27 Claims.

,My invention relates to an air conditioning System, more particularly to an air conditioning system for a plurality of enclosures, and it has for an object to provide an improved system of the character set forth.

A further object of my invention is to provide an air cooling system for a plurality of enclosures, having limited refrigeration capacity which may be selectively applied to a limited number of enclosures or to all of the same.

A still further object of my invention is to provide an air cooling system for a plurality of enclosures in which cooled air may be selectively supplied to diierent enclosures.

Another object is to provide an air conditioning system that is better adapted to meet varying air treating requirements.

When applying air cooling apparatus to certain buildings where coolingof different portions of the building may be effected at different times, a refrigerating machine of smaller capacity than that required to cool the entire building simultaneously may be used. Air cooling of residence is an example of an application of this kind, where the living quarters may be cooled during the day time and the sleeping quarters at night. It

will be apparent that rst cost, together I'with operating cost will be lower in an'installation having a relatively small refrigerating machine over an installation where all of the enclosures in the building are simultaneously cooled by a relatively large refrigerating machine.

There may be times when cooling and ventilation of all of the enclosures are desired and this feature is provided in a system constructed in accordance with my invention. It will be apparent that the total number of heat units abstracted from the air when cooling a larger number of enclosures is substantially the same as when cooling a smaller number, and therefore the reduction in dry bulb temperature of the air is less when cooling the larger number. Furthermore, in an installation in which air is cooled at a central point and distributed to the enclosures, when a given amount of air is distributed among the larger number of enclosures, each enclosure receives a smaller amount of air than if said given amount were delivered to the smaller number of enclosures. The reduction in the amount of air and its limited cooling reduce its cooling effect to a substantial'degree. These deficiencies may be offset. to some extent by increasing the total amount of air circulated to the enclosures.

In accordance with iny-invention, I provide air treating apparatus for heating and cooling air and ducts for conveying the treated air to the respective enclosures. The ducts may be provided with dampers for controlling the ow of air therethrough. Variable air circulating means, such as a variable speed blower, is preferably associated with the air treating device and functions to translate treated air to the enclosure.

A switching device which is manually adjusted is provided for selectively operating the various elements of vthe system. In a rst position of the device,`,the heating apparatus is rendered operable and in second and third positions, the cooling apparatus is rendered operable. When the heating apparatus is operable, as in the first position, the air translating means operates under thermostatic control in such manner that, when the enclosures call for` heat, heated air is translated to the enclosures at a high rate, and, when the demand for heat is satisfied, the heated air is translated -at a low rate. Heat is therefore delivered to the enclosures continuously and in such a manner that, during the periods when the thermostats of the enclosures are satisfied, the amount of heat delivered to the enclosures partly compensates for the heat loss therefrom.

When in the second position, the switch device conditions the duct system and the air translating means so that cooled air may be supplied to a portion of the enclosures, which are selected by a second switching device. In this position, the cooling apparatus is under control of a thermostat associated With'said enclosures, and the full capacity of the air cooling apparatus is utilized so that the air delivered to the enclosures by the blower, is of 'a relatively low temperature.

When the switching device is adjusted to its third position, the duct system is so conditioned that cooled air is delivered to all enclosures and the cooling apparatus is under control of one of ythe thermostats associated with the enclosures. The full capacity of the air cooling apparatus is used, but being of limited capacity, it will be apparent that the temperature drop of the cooled air will' be relatively small. In order that the reduced cooling effect of the air supplied to each enclosure and the reduced quantity of thesame may be partly oiset, I propose to increase the amount of air delivered to the enclosure by lncreasing the rate of delivery of the air translating means, as by increased blower speed.

I prefer to use the same blower which may be of the variable speed type and duct system for translating and conveying heated or cooled air,A as variable air circulation is needed when cooling or heating. It may be desirable in practice to operatefthe blower when heated air is translated at high and low speeds which differ from those used when cooled air is circulated, so that means are provided for accomplishing this result. The means employed preferably includes an auto transformer for varying the potentials impressed on the blower motor for adjusting its speed. k Y

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part ofthis application, in which:

Fig. 1 is a diagrammatic View of an air conditioning system arranged in accordance with my invention;

Fig. 2 is a schematic wiring diagram of the electrical circuits for controlling the apparatus shown in Fig. 1; and,

Fig. 3 is a diagrammatic view of a detail employed in the system.

Reference will now be had to Fig, 1 which shows a building I0 having a plurality of rooms or enclosures II to I4, inclusive, and having my novel air conditioning system applied thereto. The building further includes a basement I5 in which an air treating device I6 is'preferably disposed. The air treating device I6 comprises a casing I1 within which an air cooler or evaporator` I8, an air heater I9, anda humidifying device`20 are disposed. Ablower 2| is arranged within a chamber 22 at the inlet end of the casing I1, which blower is preferably driven by a variable speed motor 23.

The chamber 22 communicates with the enclosures II to I4, inclusive, by means of return ducts 24, 25, and 26 having electrically-operated dampers 21, 28, and 29, respectively, connected therein. The chamber 22 also communicates with the outside atmosphere through the conduit 3I. The casing I6 is also connected with the enclosures II to I4, inclusive, by means of supply ducts 32, 33, and 34 having electrically-'operated dampers 35, 38,1and 31, respectively, connected therein.. f

The blower 2l induces flow of outside air through the conduit 3I kinto the chamber 22 and also withdraws recirculated air from the enclosures I I to I4, inclusive, through the ducts 24, 25,'and 25. Outside and recirculated air commingle in the chamber 22 and the mixture is translated by the Iblower 2l through the air treating device I6 to the supply ducts 32, 33, and 34 from which itis discharged into the enclosures II to I4. During its passage through the air treating device I6, the translated air may be heated, humidied or cooled depending upon which of the devices is operative at the time.' Byopening al1 of the electrically-operated dampers, treatedair may be supplied to` all of the rooms simultaneously or, by closing some of the dampers, the air may be selectively supplied to one or moreiof: ,the enclosures.

The air conveyed to the enclosures may be heated in any'convenient manner, as by the heater I9 which is supplied with heating medium, for example, steam, from a boiler 38. The latter may be lheated by an oil burner 39, driven by a motor 49|,pr by other suitable heating means.

The operation of the oil burner 39 may be controlled by apressure switch 62 for providing a supply of steam'at a predetermined pressure in the boiler 38. This method of control is old in the art and a detailed description of the control elements is not deemed necessary. However,

when the steam pressure in the boiler 38 drops to a predetermined minimum, the pressure switch 62 closes and'operation of the burner 39 is initiated. When the pressure of the steam in the boiler 38 has been increased to a maximum determined by the adjustment of the pressure switch 62, the burner 39 is stopped. The steam pressure in the boiler 38 is therefore maintained between upper and lower limits.

Y. Steam is conveyed to the heater I9 by a conduit 4I having a valve 42 connected therein. The valve 42 is operated by a thermostatic device 43 having a thermostatic bulb 44 disposed adjacent the discharge side of the heater I9. As thermostatically-operated valves are well known in the art, no'detailed description of the same is deemed necessary. However, the arrangement is such that, as the temperature of the air discharged by the heater I9 rises, the pressure within the bulb 44 rises and the device 43 causes the valve 42 to move in a closing direction to decrease the supply of steam conveyed to the heater I9. Air discharged from the heater I9 is therefore maintained substantially at a predetermined temperature. If desired, outside temperature compensation may be provided by a second thermostatic bulb 45 disposed in the outside atmosphere and so arranged that it calibrates the device 43 so that the temperature of the air discharged by the heater I9 varies inversely with the outside temperature.

In my copending application` entitled Air conditioning apparatus, No.' 707,539, filed January 20, 1934 and assigned to theassignee of the present application, I have disclosed and claimed a j heating system having a: motor driven blower, the speed of which lis thermostatically controlled and anv automatically controlled heater including outside temperature compensation.

YThe humidifying device 20 includes a nozzle 46 supplied with water from any convenient source through a pipe 41 having a valve 48 connected therein. The valve 48 is preferably electrically operated such as, for example, by a solenoid 49. The humdifying device 28 further includes a target 5I. Water is discharged by the nozzle 46 in a fine stream against the target 5I which breaks `the stream into fineparticleswhich are vaporized and taken up by the air as it passes through the casing I1.

The air cooler or evaporator I8 mayA be supplied with refrigerant from a refrigerating machine 53, preferably of the compressor-expander type. The refrigerating machine includes a motor 54 for driving a compressor 55 which operates. to withdraw gaseous or spent refrigerant from the evaporator I8 through a conduit 56.

Gaseous refrigerant is compressed by the compressor 55 to a relatively high pressure and is discharged into a condenser 51 in which it is cooled and liquefied. Liquid refrigerant is conveyed by a conduit 58 to an expansion device 59 in which its pressure is reduced to the relatively low pressure maintained in lthe evaporator I8. When subjected to the low pressure of the evaporator I8, theliquid refrigerant vaporizes and abstracts heat from the evaporator I8 in a well known manner. The cycle is then repeated.

The various elements of my novel system may be'selectively controlled by means of a multiposition, switch 6I preferably disposed in the base member I5 adjacent the air treating apparatus. The switch 6I may be adjusted to a plurality of positions A, B, andr C for eiecting different op'- erations. When in position A, which is the winter or heating position, the dampers are all opened so that heated air is circulated to all enclosures. In this position, the heating apparatus andthe humidifying device arefrendered operable. When moved to position B, only one of the supply and one of the return dampers Aare opened and the cooling apparatus is rendered operable. Cooled air is transmitted to a portion o-f the enclosures in this position by the blower which operates at low speed. When the switch 6I is adjusted to position C, cooled air is transmitted to all enclosures by the` blower which operates at high speed. All dampers are open in this position.

Automatic temperature control of the air inthe building I0 may be obtained by providing a heating thermostat 63 having a control bulb 64 which is preferably exposed to the air withdrawn from they various enclosures II to I4, inclusive. As

shown in the drawings,`the bulb is disposed adja,

cent the recirculated air inlet to the air treating device I6 where the mixture ofthe streams of recirculated air conveyed by the ducts 24, 25, and 26 may contact it. The temperature .of this mixture represents an average temperature of the air in the various enclosures. The thermostat 63 is disposed in convenient location,`I for example, en-

closure I3, where it may be readily adjusted, as by a turning screw 63a.

The thermostat 63 controls the speed of the motor 23 in accordance with the temperature of the Aair in the building I6 so that, when it is calling for heat, the motor operates at high speed' and, when satisfied, the motor operates at low speed.

Automatic control of the humidity yof the air in the building IIl is provided byl a humidistat 65`so disposed that an average of the humidity conditions in the various enclosures is reflected therein. As shown, a hallway 66 is selected for the location of the humidistat 65 for this purpose. The humidistat 65 operates the/valve 48 by energizing or deenorgizing the solenoid 49. When the humidity of the air is above a predetermined amount, the solenoid 49 is deenergized and the valve.48'is closed vso that the supply of water to the spray nozzlev46 is stopped. As the humidity of the air in the building I0 drops to a predetermined amount, the humidistat 65 energizes the solenoid and the valve 48 opens. Water is sprayed in a finely divided condition within the casing I'I and is vaporized andtaken up'by the air delivered to the various enclosures. A switch 61 is provided for rendering the humidistat 65l operative and inoperative. Automatic control of the reirigerating machine 53 is obtained during cooling lperiods by means of' thermostats 68 and 69 which aref disposed in lenc1osures`I 3 and I2, respectively. The thermostat 68 includes a control bulb 1I arranged within the duct 24 whereby changes in temperature of the air withdrawn from`l the enclosure"'|4 are readily reiiected, therein. The thermostat 69 has a control bulb I2 arranged within the duct 25 so that -it may be contacted by a mixture of withdrawn'air from the enclosures il and I2. It'will be seenJ that the thermostat 68 controls the temperature of'the air in enclosure I3 while the thermostat 69 controls the temperature of the air in the enclosures II and` I2. Screws 68a and 69a are provided for adjusting the thermostats 68 and 69.

When the switch 6|- is in its position B, cooled air may be supplied either to the enclosures II and I2 or to the enclosure I3. The enclosures to receive cooled air are selected by a double-throw switch 13 conveniently arranged for the use of the operator'.` y When the switch is in position U, the dampers 36 and 28 are opened so that cooled air is supplied to the enclosures II and I2. The thermostat 69 is also rendered operable to control the refrigerating machine 53 in this position. When moved to the position L, thelower enclosure I3 receives cooled air as the dampers 35' and 21' are opened and the thermostat 68 is rendered' operable to control the refrigerating machine 53.

A double pole switch'14 is associated with the enclosure I3 and may be operated to manually discontinue operation of the 'refrigerating machine 53 and the blower 2I at the will of .the operator. A single pole switch 15 is also provided so` that the blower 2I may be operated for ventilation without air cooling. Similarly, the enclosures II and I2 are provided with corresponding switches 'I6 and 11. As pointed out heretofore, the motor 23 driving the blower 2I"is operated at low speed during periods when the switch 6Iy isin its position B. l

When the switch is moved to position C, cooled air is delivered to all of the enclosures as all of the dampers are opened. When in this position, the thermostat 68 or 69 which is effective to control the operation of the4 refrigerating machine. 53 is determined by the position of the switch l|3.k For example, if the switch 13 is in position U, and cooledair were being delivered to ail of the enclosures, the thermostat 69is effective to control the operation of the refrigerating machine 53.

The varlouselectrical connections vbetween the.

members for actuating switches orcontacts are 'Y designated by letters of the alphabet and the switches or contacts controlled therebyare designated by the same letter followedby a numeral.

The electrical controll and power devices receive electrical energy from main conductors 89, 8|, and 82 which are preferably' connected to a source of 3-wire single phase current. Relatively high voltage current, for-example, at 22) volts, is available for power purposes from conductors and 82 and lowerv voltage current, for example, at volts, is available from conductors 8I and 82 for control purposes.

A plurality of contacts A-I to A-8, B-I to B--8, and C-I to C-8 are all members of the switch 6I and are opened and closed when the `switch .6I is adjusted from one position to an*- othe'ra The arrangement is such that the contacts, whose reference characters contain the letter Whichindicates the position of' the switch to A-8 are closed and contacts B-I to B8 andv C-I toc-8 are open. `The blower motor 23`operates at variable speed and preferably is of the induction type having ield windings which may be connected to provide different numbers of poles. Relay switches D-I, D-2, and E-I areconnected in the conductors of the motor`23 and so arranged that, when switches D-I and D-2 are closed, the motor operates with a predetermined number of poles, for example, 6, t one speed and, when switch -E--I is closed, it operates with a higher number of poles, forA example, I2, at a lower` speed. Both the high and the low speeds of the tothe steam conduit 4| said predetermined degree.

'I provide a transformer motor may be furtherl adjusted by varying the potential impressed on the motor windings. An auto transformer 83 connected across the conductors and 82 is preferably used for this p'urpose and includes a-plurality of taps 84 to 81, inclusive, which are adjustable. Relay switches F-I, G-I, H-|, and J-I are connected between the taps and-a conductor 88 connected to the motor 23. It will be apparent that two speeds are provided for 6-pole operation and two for 12-pole operation. One of each may be used when the system is heating and another of each when the system is cooling. The switches D-I and D-2 are operated by a relay solenoid D so that they close when the latter is energized. Switch E-I is operated by a relay solenoid E and is closed upon energization of the latter. The switches F-|, G-"I, II|, and J| are respectively operated by relay solenoids F, G, H, and J in such manner that energization of a solenoid closes its respective switch.

'I'he oil burner motor 40 is energized by conductors 8| and 82 when a relay switch P| is closed. The latter is moved to its closed position by a relay solenoid P when the latter is energized. The pressure switch 62 is connected in series with switch A| and with ,the primary of a transformer 89, the secondary'oi which is connected to the relay solenoid P. The primary of the transformer 89 is energized through conductors 8| and 82 when the switch A-l and pressure switch 62 are closed.I

The solenoid 49 for operating the water valve 48 is energized through conductors 8l and 82 and a circuit which includes the humidistat 65, the switch 61, and the switch A-3. A thermostat 90 is preferably included in the circuit of thesolenoid 49, which thermostat is attached near the valve 42. This thermostat is so arranged that its contacts are closed when the temperature of the pipe 4| adjacent the heater is above a predetermined degree and are opened when the temperature is below The purpose of this thermostat is to render the humidiiying device 20 and the blower 2| inoperative when the apparatus is adjusted for heating, and the supply of steam furnished by the boiler 38 fails, this being effected by opening ofthe contacts of thermostat 90. The thermostat 90 therefore functions as a protecting device which prevents circulation of cold air when the supply of heating medium fails. "I'he circuits leading through and G also include the thermostat 90 when the apparatus is adjusted for heating, and cannot be energized unless the thermostat 90 is closed.

The thermostat 90 is connected in parallel with the contacts B-I and C-ifone of which is 'closed when the system is cooling. Circuits through the relay solenoids D, E, H, and'J are completed through either of the contacts B-i and C-i during cooling operation or through the thermostat 90 when the system is heating.

The heating thermostat 63 controls the circuit through a relay solenoid K which operates switches K-i and'K-2. The operation is Asuch that, when the relay solenoid K is deenergized, switch K-2 is closed and switch K-'l is open. When the solenoid K is energized, the reverse is true with K-i closed and K-2 open.

1t is desirableto operate some of the control elements, such as thermostats and the damper operating motors, at low voltage.- Accordingly, |0|, the primary winding cated at |35, |36, and |31, respectively. The

through the building l0 the solenoids D, E, F,

' deenergized after it had moved the damper valve |04 through an angle of 90 to open position, as

of which is connected across the conductors 8| and 82 and the secondary of which is connected across and energizes the main low voltage conductors |02 and |03. The transformer may provide, for example, a voltageot- 25 volts. The cooling thermostats and the damper operating motors are connected across the' conductors |02 and |03 as is clearly shown in Fig. 2.

The motor 54 of the refrigerating machine 53 is energized preferably from conductors 80 and 82 through a relay switch M-|, the latter being operated by the solenoid M. The solenoid M is preferably connected across the conductors 8| and 82 through a relay switch N--I and contacts by a solenoid N, one terminal of which is connected to conductor I 02 and the other terminal to the cooling thermostats 68 and 69. 'I'he thermostat is connected to one pole of the switch 14, which is connected by means of a conductor 9| with the contact 92 of switch 13. The thermostat 69 is connected to one pole of the switch 16, the latter being connected by means of a conductor 93 to the contact 94 of the switch 13. One side of each of the switches 15 and 11 is connected to a conductor 95 which leads to the relay coils D, E, F, G, H, and J through contacts C-3 or B-3. The otherl side of the switch 15 is connected to a contact 96 of the switch 13, and the opposite side of the switch 11 is connected to a contact 91 of the switch 13. The switch 13 includes blades 98 and 99, the former of which is adapted to engage contacts 94. or 92 and the latter is adapted to engage contacts 91 and 96. The blade 99 is connected to the conductor 82 through contacts B-4 or C-4 andthe blade 98 is connected to the low voltage main conductor |03 y through contacts B-5 or C--5.

The electrically-operated dampers 21 to 29, inclusiye, and 35 to 31, inclusive, include, preferably, reversible motors for bpening and closing the same.' The motors for the dampers 21, 28, and 29 are respectively shown at |21, |28, and |29. The motors for dampers 35, 36, and 31 are indimotor-operated dampers are similar and a diagram of the one which controls the duct 24 is shown in Fig. 3, in its `closed position. The motor |21 drives a damper valve |00 through speed reducing gearing |05, and limit switches |06 and |01 are provided to stop the motor |21' when the valve'l04 has been moved to the limits of its travel; The switches |06 and |01 are actuated by a cam |08 which operates to open the switch through which the motor |21 is energized, when thev limit of movement of the valve |04 has been reached. Assuming the valve |00 to be in the position shown in Fig. .3, the motor |21 would be energized through switch |06 and the cam |08 would then have moved the switch |06 to its open position.' v

The motor-I 21 may be of Vany suitable reversing type such as, for example, a series wound motor having a split iield. When the circuit through the motor includes the armature and one portion of the eld winding, the motor operates in one direction and, when the circuit includes the armature and the other portion of the field winding, the motor operates in a reverse direction. The armature and split field connections are shown in Fig. 2. The limit switches for the other motors -|28, |29, and |35 to |31, inclusive, are shown at |08 to H1, inclusive. In this connection, it will gized to open their dampers.

al1 limitY switches, through which the various` damper motors are energizedl to close the dampers, by oddK numerals |01,|09, ||3, H5, and y| I1.

Even numerals are used to designated the limit switches through which the damper motors are' energized for opening the dampers.

The damper motors are` relatively small so I prefer to operate them from the secondary of the lo w voltage control transformer |i. A-6, A-1, A-8, B-6, B-8, 0 6, C-1,.and C- associated with switch 6|, are connected in the control circuits of the damper motors for controlling the same. motors |21, |20, |36,'and |36 also include contacts |20 to |23, inclusive, of the switch 13. As stated heretofore, switch 13 is used for selecting the'enclosures which are to receive cooled air when the main control switch is in position B and therefore the circuits leading through the damper motors which control the iiow of 'air to enclosures which are selectable for cooling, are controlled by switch 13. The contact I2 of switch13 is connected to limit switches H0 and |12 of motors |28 and |36. These limit switches are the ones through which the motors are ener- The contact |211 connects to limit switches |01 and |00 of motors |21i andv|35 which switches complete circuits through the`r motors to `eiect closing of their dampers. Adjustment of switch 13 to its position U operates these motors to open dampers 28 and 36 and to close dampersZ'l and 35. Contacts |22 and |23 connect to the other limit switches |06, |08,.|ii, and H3 so` that, when switch 13 is moved to position L, the motors are operated to close dampers 28 and 36 and to open dampers 21 and 35.

Jthe air in the building |-0is above the degree at which the thermostat 63 closes and that the thermostat 90 is closed as the temperature of the steam supplied by the boiler 38 is above the temperature at which the thermostat 90 opens. With these conditions, the various switches are in the positions shown in Fig. 2. The dampers are all open as all of the damper motors have been energized through contacts A-6, A-1, and A--8, which are connected to limit switches ||6 and H4, ||2 and H0, and |08k and respectively.

As the temperature ofthe air in the building 1s above the minimum degree to be maintained, the contacts of the thermostat 83 are open and solenoid K is deenergized. Therefore, the contacts K-i are open and contacts Kp-2 vare closed. A circuit may be traced from the line conductor 8|, thermostat 90, solenoid E, contacts K2, and A-2 to the lineconductor 82. As the solenoid G is connected in parallel with the solenoid E through the contacts A-4, it will also be energized. The relay switches E-i and.G-| are therefore closed to energize the motor 23. The

switch E-| connects to the low speed winding of the motor 23, or in the example given the 12-pole winding. The motor 23 is connected to the auto transformer 83 throughl the conductor 88, relay switch G-I and the tap 81. Low speed operation of the motor 23 at the desired voltage is therefore obtained.

Contacts 'I'he circuits includingl 'I'he blower 2| circulates heated air for ventilation to all of the enclosures in the building i0 at a relatively low rate which partly compensates for the hea't loss from the building. When the temperature of the air in the building drops to a predetermined degree, the contacts of the thermostat 63 close and the solenoid K is energized by the secondary of the transformer i0 i The circuit may be traced from the conductor |02, contacts A-6, thermostat 63, solenoid K, to conductor |03. -Contacts K-i are therefore closed and the lcontacts K-2 opened to deenergize the solenoids E and G with the resultant opening of the relay switches G-i and E-i.. Closing of the contacts K-i energizes the solenoids D and F, the vlatter being connected in parallel with the former through the contacts A-3. The circuit through the solenoid D is completed from line, conductor 8i, thermostat 90, solenoid D, closed.

` contacts K-i, contacts A-Z to line conductor 82.

Energization of the solenoid D closes the contacts D-i and D-2 and completes the high speed or 6-pole connection of the motor 23. Energization of the solenoid F closes the relay switch F-i to connect the motor 23 to the transformer 83 through the conductor 88 andtap 8d. The motor therefore operates. at high speed and at the desired voltage; the enclosures at a relatively high rate and continues as long as the thermostat 63 maintains its contacts closed.

The operation of the oil burner 38 is controlled in accordance with the pressure of the steamin the boiler as heretofore pointed out.- The pressure switch 62 shown in Fig".l 2 is open which indicates that the steam pressure in the boiler is above the predetermined minimum amount to be maintained. ,When the pressure of the steam in the boiler falls b elow this amount, the pressure switch contacts 62l close to complete a circuit from the conductor- 8i, contacts A-i, the primary of the transformer 88, and pressure switch contacts 62, to the line conductor 82. Solenoid P is therefore energized from the secondary of the transformer 89 and 'closes' its switch P -i. Closing of the latter energizes the burner motor 4, the circuit of which. may be traced from the lineconductortli, motor 40, switch P-I to the conductor 82. Whenn the pressure in the boiler has been raisedV to a predetermined amount, the pressure switch .62 opens its contacts and the solenoid P is deenergized. 'I'he contacts P-i are opened and operation of the motor 40 is terminated.

The humidifying device` is operative during the heating operation of the system, and is preferably operated to humidify heated air when the humidity of the air in the enclosures falls below a predetermined amount and only during periods when heated air is delivered to the enclosures at a high rate. The solenoid 49, therefore,r is controlled by the humidistat 65 and thermostat 63; being energized only when both are closed in response to low humidity and low temperature, respectively. The circuit for the solenoid 49 may be traced from the conductor 8|, thermostat 90, contacts A-3,'solenoid 49, humidistat 65, switch 61, contacts K-|, and contacts A-2, to fthe line conductor 82; the solenoid 49, humidistat 65, and switch 61 being connected in parallel with the relay solenoid F, which is energized when heated air is supplied to the enclosures at a high rate. 'I'he energized solenoid 49 opens its valve 48 and water is supplied to the nozzles 46 to be sprayed and taken up by the air. When the humidity of ,the air inthe building has been increased toa Heated air is delivered to all of A predetermined amount, the humidistat 65 opens its contacts, and the supply of water to the nozzles @36 is terminated.

if the temperature of the air is above the degree to be maintained by the thermostat 63, the switch K-l is open due to the deenergized condition of the solenoid K. Humidiiication ceases in this event as the circuit through solenoid 49 is broken at K-I. This method of operation is preferred, as it is desirable to humidify air only when it is being conveyed to the enclosures at a high rate in response to a demand for heat.

When it is desired to cool a portion of the enclosures, the main switch 6i is moved to its position B. 'All of the contacts A-ll to .li-9 are therefore opened and the contacts B- to B-8 are closed. Opening of the contacts A-i breaks the circuit of the oil burner motor 39, and the humidifying device 20 is rendered inoperative as the circuit including solenoid 49 is opened at ii- 3. The relays F and G are also rendered incapable of energization by the opening of contacts 11i-3 and vA--IL respectively. Opening of contacts A-5 renders the thermostat 63 inoperative and solenoid K is deenergized so that its switches K-l and K-2 are open and closed, respectively. The`contacts A-6, A-'d, and A- open, but for the moment this is of no import as the circuits including these 'switches are broken by the damper motor limit switches i106, E08, ill), M2, H4, and H6.

Contacts B-t, B-`l, and B-8 are closed; the icrmer completing a circuit from the conductor 902, contact B-6, limit switch lill, motor H31 to conductor 03. A circuit is also completed i through limit switch H5 and motor 29 as these motors its and 931 are parallel connected. The motors |129 and 031 operate to close the dampers 29 and 3l! so that treated air cannot be conveyed through the ducts 34 or 26. The enclosures to receive treated air are selected by adjustment of the switch t3. Assuming it is desired to furnish cooled air to the upper enclosures ll and i2, the switch i3 is'moved to its position "U, A circuit is thereby completed through contacts B- switch'l3, contact l2l, and the limit switches B99 and H91 to the damper-closing windings of the motors i135 and 121, to close the dampers 21 and 35. This operation cuts oi the supply of air through the duct 32 to the enclosure i3, and the return through the duct 24. The dampers 28 and 36 remain open so that cooled air may be circulated through the duct 33 to the upper enclosures ll and i2. l

As it is desired to circulate cooled air to a ilmited number of enclosures at a relatively low rate as pointed out heretofore, the blower 2l will loe operated at low speed which necessitates the closing of relay switches E-i and J-'i. These are closed by the energization of 4their respective solenoids E and J, the circuits through the former being traced from the line conductor 9 I contacts B-L solenoid E, contacts B-3," conductor 95, switch 716, or TI, contact 91, switch blade 99, contact IB-4 to the line conductor 92. The solenoid J is also energized as it is connected in parallel with the solenoid E by means of the contacts 3 2. enclosures Il and l2 is rendered operative to control the refrigerating machine 53 when the switch i3 is moved to its position U. if the temperature in the enclosures Il and l2 is above the degree for which the thermostat 69 is set, the contacts of the latter will be closed. A circuit will, theretore. be established from conductor lll, solenoid position,

'The thermostat 69 associated with the Cooled air is circulated at a low rate by the l blower which now operates at low speed, through the duct 33 to the enclosures il and i2. rl'he air is withdrawn from these enclosures through the duct 25 to the chamber 22 where it is mixed with asupply of air from outside the enclosure. When the temperature of the air in the enclosures it and i2 has been reduced to the desired degree, the thermostat 69 opens its contacts and the solenoids N and M are both deenergized. This, of course, terminates operation of the compressor motor 54.

it will be apparent from the foregoing that the compressor motor 54 may be stopped manually at any time by opening switch "i6, This would also terminate operation ofl the blower motor 23. The blower El may 'air -without cooling, however, by closing switch opposite position L. This would render the ther- 'mostat E8 effective to control the refrigerating machine and would also cause dampers 35 and 2l to open and dampers 36 and 28 to close. The operation of the system during the periods that cooled air is supplied to the enclosure i3 is the same as when supplied to the enclosures it and i2, except that cooling and circulation are controlled by thermostat 58 and switches it and l5 similarly to and instead of thermostat e9 and switches i6 and ill. i

When cooled air is to be furnished to all of the enclosures in the building l0, di is moved to its position C. in this position, the blower 2| is operated at full speed in order that the supply of air delivered to each enclosure may be increased over the amount which would be delivered at the ited number of enclosures. All of the dampers are open when the contacts C-B, 0 7, and C- are closed as these switches energize the damper opening windings of the damper motors through the limit switches 006, 98, H0, M2, M4, and M6.

The operation of the compressor motor E34 is controlled by either thermostat 68 or 69, depending upon the position of the switch i3. The'controlling circuits of the thermostats t8 and 69 are the same as .when the main switch is in its B one exception being that contacts C- complete the circuit instead of contacts B-l As the blower motor 23 is to operate at high speed, switches D-l, D-2, and H-l are closed.

speed used when cooling a limf be operated to circulate the main switch Thelrelay solenoids D and-H are therefore ener-` gize'd, the circuit through the former extending l `from conductor 8l, contacts C i, solenoid D,

contacts C-3, conductor 95, switch l5 or l'Lj parallel with solenoid D through contact C-2 'so that it is energized simultaneously therewith. The switches D-I and D2 connect the high speed or 6-pole connection of the motor 23 to the transformer 83 through the switch H-I; the proper voltage being obtained by adjustment of the tap 85.

From the foregoing, it will be apparent that I have provided an air cooling system having refrigerating means of limited capacity which may be operated to circulate air at a given rate through a limited number of enclosures, the temperature of which air ,has been substantially depressed; and, secondly, may be also operated to circulate air whose temperature has been depressed a relatively small number of degrees to a larger number of enclosures and at a higher rate. The results obtained from both methods of operation using substantially the same amount of refrigeration, are a reduction in the effective temperature of the air in the enclosures.

While I have shown my invention in but one form, it willbe obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In an air conditioning system for a plurality of enclosures, the combination of means for heating the enclosures, means for cooling the enclosures, a single control device movable to a plurality of selective positions, means effective in one position of said/v device for rendering the heating means operative, means effective in a second position of the device for rendering the cooling f means operative and for applying the full capacity thereof to a limited number of enclosures and means effective in a third position of the device for rendering the cooling-means operative and for applying the full capacity thereof to a larger number of the enclosures.

2. In an air conditioning system for a plurality `of enclosures, the combination of means for heating air, means for cooling air, means for translating the treated air, a plurality of ducts for conveying the treated air to the enclosures, a single control device movable to a plurality of selective positions, means'eifective in one position of said device for rendering the air heating means operative and for conditioning said ducts so that heated air is conveyed to alrelatively large number of the enclosures, means effective in a second position of the device for rendering said cooling means loperative and for conditioning the ducts so that cooled air is conveyed to a relatively small number of the enclosures, and means effective in a third position of the device for rendering the Icooling means operative and for conditioning said ducts so that cooled air is conveyed to a relatively large number of enclosures.

3. In an air conditioning system for a plurality of enclosures, the combination of means for heating air, means for cooling air, means for translating the treated air, a plurality of ducts for conveying the air translated by the last-mentioned means to the enclosures, a control device movable to a plurality of'selective positions, means effective in one position o-f said device for rendering y the air heating means operative and for conditioning said ducts so that heated air is conveyed to a relatively large number of the enclosures, means effective in a second position of the device fo-r rendering said cooling means operative and for conditioning the ducts so that cooled air is ,conveyed to a relatively small number of the enclosures, means effective in a third position of the device for rendering the cooling means o-perative and for conditioning said ducts so that cooled air is conveyed to a relatively large number of enclosures, thermostatic lmeans responsive to the temperature of the air in the enclosures for controlling the air translating means when the control device is adjusted to said one position, a plurality of thermostats associated with the enclosures for controlling the operation of the air cooling means when operative, and means associated with said control device for selectively rendering one of said thermostats operative when the control device is adjusted to its second or third positions.

4. In an air conditioning system for a plurality of enclosures, the combination of means for heating air, means for cooling air, a variable speed blower for translating the treated air, va plurality of ducts for conveying the treated air from the blower to said enclosures, a control device movable to a plurality of selective positions, means effective in a first position of said device for rendering said air heating means effective and for conditioning said ducts to convey heated air to all of the enclosures, means eective in a second position of said device for rendering said air cooling means operative for conditioning the ducts to convey cooled air to 'a relatively small number of enclosures and for operating said blower at its low speed, means effective in a third position of said control device for rendering the air cooling i means operative, for conditioning said ducts for conveying cooled air to a relatively large number of enclosures and for operating said blower at its high speed, thermostatic means operative in said one position of the device for controlling the operation of the blower so that it Voperates at high speed when the thermostatic means is calling for heat and at low speed when the latter is satisfied, a plurality of thermostats associated with the enclosures and adapted, when rendered effective, to control the operation of the air cooling means, and means associated with the control device for selecting the thermostat whichl is operative to control the air cooling means; said lastmentioned means being also adapted to select the enclosure or enclosures which receive cooled air when said control device is in its second position.

5. In an air cooling system for a plurality of enclosures, the combination of refrigerating means of limited capacity, a single control device movable to a plurality of selective positions for controlling the application of the cooling effect of said refrigerating means to the enclosures, means controlled by said device when in one position for applying the cooling effect of said rc- 'frigerating means to a limited number of enclosures, and means controlled by said device when in another position for applying the cooling effect of said refrigerating means to a larger number of enclosures.

6. In an air cooling system for a plurality of enclosures, the combination of means for translating air for said enclosures, refrigerating means of limited capacity for cooling said air, a plurality of ducts for respectively conveying the cooled air to said enclosures, a single controlidevice movable to a plurality of selective positions, means responsive to one position of the control device for conditioning the ducts so that air is conveyed thereby to a limited number of enclosures, and means responsive to a second position of the control device for conditioning the ducts so that air is conveyed to a larger number of enclosures.

'7. In an air cooling system for a plurality of enclosures, the combination of means for translating air for said enclosures, refrigerating means of limited capacity for cooling said air, a plurality of ducts for respectively conveying the cooled air to said enclosures, a single control clevice movable to a plurality of selective positions, means responsive to one position of the control device for conditioning the ducts so that air is conveyed thereby to a limited number of enclosures, means responsive to a second position of the control device for conditioning the ducts so that air is conveyed to a larger number of enclosures, and means eiective in both selective positions of the device for rendering said refrigerating means operative.

8. In an air cooling system for a plurality ot enclosures, the combination of means for translating air for the enclosures, refrigeratlng means for cooling said air, a plurality of ducts for conveying the cooled air from said refrigerating means tothe enclosures, each of said ducts being arranged to convey air to one or more of the enclosures, dampers for controlling the flow of air through the ducts, a plurality of thermostats responsive respectively to the temperature of the air in the enclosures served by the ducts for controlling the operation of said refrigerating means, switching means movable to a plurality of selective positions, means effective in one position of the switching means for positioning said dampers to supply cooled air to a limited number of enclosures under control of their respective thermostat, means effective in another position of the switching means for positioning the dampers to `supply cooled air to a larger number of enclosures under control of one of said thermostats, and means effective in both positions of the switching means for rendering said refrigerating means operative to cool the air translated by the air translating means.

9. In an air cooling system for a plurality of enclosures, the combination of a variable speed blower for translating air for said enclosures, means for cooling the air, adjustable means movable to a rst position for operating said blower at its low speed and to a second position for operating the blower at its high speed, means controlled by said adjustable means, when moved to its rst position, for conveying cooled air to a portion of the enclosures, and means controlled by the adjustable means, when moved to its second position, for conveying cooled air to all of I said enclosures.

10. In an air cooling system, the combination of means for cooling air, a variable speed blower for translating air in heat exchanging relation with said air cooling means, a plurality of ducts for conveying the cooled air to the points of use, a control element movable to different positions, means responsive to one position of said control element for effecting operation of said blower at relatively low speed and for limiting the number of ducts effective to convey cooled air,

and means responsive to a second position of said control element for effecting operation of the blower at a .higher speed and for renderingva greater number of ducts effective to convey cooled air. i

ll.. In an air cooling system for a plurality of enclosures, the combination of a variable speed blower for translating air for the enclosures, means for cooling the air, a plurality of ducts for respectively conveying the cooled air to the enclosures, dampers associated with each duct, adjustable means movable to a ilrst position in which said blower is operated at low speed and to a second position inwhich the blower is operated at high speed, means for operating said dampers so that cooled air is translated to a number of enclosures less than the total number thereof when said adjustable means is moved to its first position, and means for operating said dampers so that air is translated to all of the enclosures when the adjustable means is moved to its second position.

l2. In an air cooling system for a plurality of enclosures, the combination of means for translating air for the enclosures, means for cooling said air, ducts for respectively conveying the cooled air to the enclosures, dampers associated with said ducts for controlling the flow of air to the enclosures, a switch associated with each of a plurality of said enclosures for controlling the operation of the air cooling and the air translating means, a selector switch for selectively rendering the last-mentioned switches operable and inoperable, and means associated with the selector switch for opening the dampers associated with the enclosure whose switch has been rendered operable and for closing the dampers of the remaining enclosures.

13. The system as claimed in claim 12 having means for opening all of the dampers independlating air for the enclosuresmeans for cooling the air, ducts for respectively conveying the cooled air to the enclosures, dampers associated with the ducts for controlling the flow of air therethrough, a thermostat associated with each of a plurality of said enclosures for controlling the operation of the air cooling means, a switch associated with each last-mentioned enclosure for rendering its associated thermostat operable and inoperable and for controlling the operation of the air translating means, a selector switch for selectively rendering the rst-mentioned switches operable and inoperable and for controlling the operation of said dampers so that air is permitted to flow to an enclosure when its associated switch is rendered operable by said selector switch, and means for opening all of the dampers independently of the selector switch, whereby air is delivered to all of said enclosures;

15. In an air cooling system for a plurality of enclosures, the combination of means for translating air for the enclosures, means for cooling said air. a plurality of ducts for respectively conveying the cooled air to said enclosures, dampers associated with each of the ducts, a plurality of thermostats associated with the enclosures which, when rendered operable, control the operation of the air cooling means in accordance with the temperature. of their respective encloall of the enclosures regardless of the position of said last-mentioned means.

16. In an air cooling system for a plurality of enclosures, the combination of means for translating air for the enclosures, means for cooling said air, a control device movable to a plurality of selective4 positions, means effective in one position of said device for operating the air translating means so that air is circulated at a low rate, means eiective in a second position of said device for operating the air translating means Aso that air is circulated at' a higher rate, means eiective when said control means is in said one position for distributing air to a limited number of enclosures and means effective when the control means is in said second position for distributing air to a larger number of enclosures.

1 7. In an air cooling system for a plurality of enclosures, the combination of means for translating air to the enclosures, means for varying the amount of air translated by the last-mentioned means, means for cooling the air, ducts for respectively conveying the cooled air to the enclosures, dampers associated with said ducts for controlling the ow of air therethrough, a

switch associated with each of a plurality of said enclosures for controlling the operation of the air cooling means and said air translating means, a selector'switch for selectively rendering said switches operative and for operating said dampers so that air is permitted to flow to an enclosure whose switch is rendered, operable,

means for opening all of said dampers for per- `for heating the enclosures, means for cooling the enclosures, controlmeans responsive to a single control impulse for rendering the heating means operative and for applying the heating effect to va. relatively large number of enclosures, means responsive to a single control impulse for rendering the cooling means operative and for applying the full 'capacity thereof to a limited number of enclosures, and means responsive to a single control impulse for rendering the cooling means operative and for applying the full capacity thereof to a larger number of enclosures.

i9. In an air conditioning system for a plurality of enclosures, the combination of means for heating air, means for cooling air, means for i translating the treated air, a plurality of ducts for conveying the treated air to the enclosures,

means responsive to a single control impulse for rendering the air heating means operative and for conditioning said ducts so that heated air is conveyed to a relatively large number ofthe enclosures, means responsive to a single control impulse-for rendering said cooling meansoperative and for conditioning the ducts so that cooled air is conveyed to a relatively small number of the enclosures, and means responsive to a single control impulse for rendering the cooling means operative and for conditioning said ducts so that cooled air is conveyed to a relatively large number of enclosures.

20. In an air coolingsystem for a plurality of enclosures, the combination of refrigerating means of limitedcapacity for cooling air, control mechanism comprising a single control element movable to a plurality of positions, means responsive to one position of said control element for rendering said refrigerating means inoperative, means responsive to a second position of said control element for rendering said refrigerating means operative and for applying the cooling effect thereof to a limited number of enclosures, and means responsive to another position of said control 'element for rendering said refrigerating means operative and for applying the refrigerating effect thereof to a larger number of enclosures.

21. In an air cooling system, the combination of means for cooling air, means for translating the cooled, air, a plurality of ducts for conveying the cooled air to the points of use, a single control device movable to a plurality of selective.

positions, means responsive to one position of said device for rendering the air cooling means inoperative, means responsive 'to a second position of the device for rendering said air cooling means operative and for limiting the number of ducts effective to conveyair, and means responsive to a third position of the device for rendering the aircooling means operative and for rendering a larger number of ducts effective to convey air.

22. In an, air cooling system for a plurality of enclosures, the combination of refrigerating means of limited capacity, means including an element movable to a plurality of positions for applying the cooling effect of said refrigerating means to a relatively great number of enclosures in response to a rst position of said movable element and. for limiting the number of enclosures -to which said cooling effect may be appliedV in response to another position of said movable element, and means for selectivelyyvarying the enclosure or enclosures to which the cooling effect is applied when the number of enclosures to which it may be applied is thus limited.

23. In an air conditioning system for a plurality of enclosures the combination of refrigerating means of limited capacity, means operable from a given point or location for selectively applying the cooling effect of said reirigerating means to a limited number -of enclosures or to a greater number of enclosures, and means operable from a vgiven point or location for selectively varying the enclosure or enclosures to which said refrigerating eifect is applied when the same is applied to a limited number of enclosures.

24. In an air cooling system, the combination of means forcooling air, means for translating the cooled air, a plurality of ducts for conveying the cooled air to the points of use, a control element movable to a plurality of selective positions, means responsive to a first position of said control element for limiting the number of ducts effective to convey air from said air cooling means, means responsive to a second position of the control element for renderingl a larger cooled air to said enclosures, means responsive to a single control impulse for rendering said refrigerating means operative and conditioning the ducts so that air is conveyed thereby to a dition in the enclosure, means for humidifying the air being circulated, and means for limiting operation of the humidifying means to periods when air circulation at an increased rate is eftected,

2'7. In an air conditioning system for an enclosure, the combination of heating means, a variable -speed ian for circulating air in heatexchanging relation with said fan means and into the enclosure, means responsive to a predetermined minimum temperature in the enclosure for increasing the fan speed and responsive to-a predetermined maximum temperature for decreasing the fan speed, means for spraying water into the heated air stream, and means "for controlling said spray means, the last-mentioned means being interlocked with the fan control means such that the humidifying means cannot be operated except when the fan is operated at an increased speed'.

v JOHN F. LAMB. 

